I have a thread in Messages with my siblings that has been going on for years. Everyone on the thread is on an iPhone (and therefore using Messages), except my sister who is on an Android. On my iPhone (iOS 16) the thread works fine, receiving and sending to everyone. On my Mac, a week ago the thread stopped working – meaning, if I send a message to the thread from my Mac I get a “not delivered error”. The Mac instance of the thread is also no longer syncing with the phone and. New messages arrive at the phone and are added to the thread, but no longer to that thread on the Mac.
I’ve logged in and out of messages on the phone and the Mac several times, but this precious thread is dead on the Mac. All other threads are working on both devices.
I also cannot create a new thread / new text to my sister on the Mac. It’s like the Mac (on Ventura) just won’t send to a non-iOS device anymore.
Ugh. Any ideas on how to fix this? I can continue doing everything on the phone, of course, but I really want to have the flexibility to use Messages on both devices.
I’m not on Ventura yet, but I have long had a problem with the Mac keeping up with iMessage threads. Which is a shame, because that’s the place most suited to serving as an archive and permanent record.
I turned off messages on the Mac and the iPhone (again). Shut down both. Rebooted the Mac into Safe Mode and ran Onyx to do the maintenance that app does to clear caches, etc. REbooted the iPhone and turned on Messages on the iPhone. Sent a couple of messages to the family thread on the iPhone, where the thread has been working without issues. After a member replied, I booted the Mac and turned on Messages. The new messages appeared in the thread! There is a gap of several weeks in the thread on the Mac, but (for now) it seems to be working ok again.
Thanks for all the help offered above! It gave me an idea of how to proceed, and thankfully (so far) it worked.